#include<iostream>
#include<vector>
#include<string>
#include<algorithm>
using namespace std;

int levenshteinDistance(const string& s1, const string& s2)
{
    int m = s1.size();
    int n = s2.size();

    vector<vector<int>> dp(m + 1, vector<int>(n + 1, 0));

    for (int i = 0; i <= m; i++) dp[i][0] = i;
    for (int j = 0; j <= n; j++) dp[0][j] = j;

    for (int i = 1; i <= m; i++)
        for (int j = 1; j <= n; j++)
        {
            if (s1[i - 1] == s2[j - 1])
                dp[i][j] = dp[i - 1][j - 1];
            else
                dp[i][j] = 1 + min({ dp[i - 1][j], dp[i][j - 1], dp[i - 1][j - 1] });
        }

    return dp[m][n];
}

int main()
{
    string s1, s2;
    cin >> s1 >> s2;

    int distance = levenshteinDistance(s1, s2);

    cout << distance << endl;
    return 0;
}
